1. Field of the Invention
The present invention relates to a battery removably mounted on a video camera etc. and, more particularly to a battery used and mounted in the rear side of large-size equipment such as a video camera for commercial use.
2. Description of Related Art
In a large-size camera referred to as a camera for commercial use or for professional use, as shown in FIG. 1A, an adapter plate 3 is mounted in the rear side (the side opposite to a lens 2, and hereinafter described in like manner) of a video camera 1. A battery 4 is mounted directly in this adapter plate 3, or as shown in FIG. 1B, a box-shaped holder 5 is mounted in an adapter plate 3 and one or two battery 4 is inserted in this holder 5.
In the case of an example shown in FIG. 1A in which a detailed illustration is omitted, the adapter plate 3 is mounted in a vertical coupling surface 6 which is a back end of the video camera 1 by fitting a V-shaped engagement part into a V-shaped receiving groove in a dovetail joint manner. This joint structure is shown in, for example, Japanese Unexamined Patent Publication No. 7-143372. A mounting structure adapted for a mounting structure of the battery 4 is provided in a battery-mounting surface of the adapter plate 3. The structure is directed outward when mounted on the video camera 1. Thus, in such the structure, when a residual capacity of the battery 4 becomes a predetermined value or less, such the battery 4 shall be removed and a new battery is mounted required to use. Also, in the case of an example shown in FIG. 1B in which a detailed illustration is also omitted, the same mounting structure as that of the battery is provided in a mounting surface to the adapter plate 3 of the holder 5. In the case of this example, one of the battery 4 whose residual capacity lowers the predetermined value are removed from the holder 5 then a new battery is mounted and used.
Any of these mounting structures of the battery are convenient, but in the case of the example shown in FIG. 1A, plural batteries cannot naturally be mounted and used at the same time. In the case of the example shown in FIG. 1B, the extra structure body such as a box-shaped holder is also required though two batteries can be mounted and used at the same time.
Therefore, an object of the present invention is to provide a battery capable of simultaneously mounting and using plural batteries without requiring the extra structure body such as a holder.
In order to achieve the above object, a battery according to the present invention is characterized by a battery capable of being mounted removable in a coupling surface of a video camera etc. or an adapter plate mounted in said coupling surface, characterized in that in the battery provided with a V-shaped engagement part for fitting into a V-shaped receiving groove provided in the coupling surface of the video camera etc. or the adapter plate in a dovetail joint manner on one side, a V-shaped receiving groove with the same shape as that of the V-shaped receiving groove provided in the coupling surface of the video camera etc. or the adapter plate is provided on the other side opposite to one side of the battery to be mounted in the video camera etc. in order to join another battery having the V-shaped engagement part in a dovetail joint manner. Thus, the battery can easily be mounted in the video camera or the adapter plate mounted in the video camera and also, plural batteries can simultaneously be used by overlapping and mounting the battery in another battery in a state of being mounted in the video camera etc. and the need for the extra structure body such as a box-shaped holder is eliminated.
Also, in order to achieve the above object, a battery according to the present invention is characterized in that a circuit for outputting a self-capacitance, a terminal for inputting a self-capacitance output from another battery, and an averaging circuit for averaging an output of the self-capacitance output circuit and an input from the input terminal to produce an output are built into the battery. Thus, when plural batteries are simultaneously used, two batteries can integrally be handled to output the residual capacity.
Further, in order to achieve the above object, a battery according to the present invention is characterized in that a V-shaped receiving groove provided on the other side opposite to one side of the battery to be mounted in the video camera etc. is formed between a pair of protrusion parts protruded from the other side, and projections having a terminal for connection to another battery or another device capable of fitting in an equivalent dovetail joint manner on the top and projections for connection guide are provided on the upper parts of a pair of said protrusion parts, respectively, and another terminal for connection to another device is placed between these projections. Thus, in addition to mounting into the video camera, connection or disconnection between the batteries can be made very easily.